docstr: Test corner case where a network might predict no boxes.
docstr_tok: ["Test","corner","case","where","a","network","might","predict","no","boxes","."]
code: def test_uniform_assigner_with_empty_boxes(self):
      """Test corner case where a network might predict no boxes."""
      assigner = UniformAssigner(0.15, 0.7, 1)
      pred_bbox = torch.empty((0, 4))
      anchor = torch.empty((0, 4))
      gt_bboxes = torch.FloatTensor(
          [
              [0, 0, 10, 9],
              [0, 10, 10, 19],
          ]
      )
      gt_labels = torch.LongTensor([2, 3])
      pred_instances = InstanceData()
      pred_instances.priors = anchor
      pred_instances.decoder_priors = pred_bbox
      gt_instances = InstanceData()
      gt_instances.bboxes = gt_bboxes
      gt_instances.labels = gt_labels
  
      # Test with gt_labels
      assign_result = assigner.assign(pred_instances, gt_instances)
      self.assertEqual(len(assign_result.gt_inds), 0)
      self.assertEqual(tuple(assign_result.labels.shape), (0,))
  
file_path: mmdetection/tests/test_models/test_task_modules/test_assigners/test_task_uniform_assigner.py
imports: from unittest import TestCase
  import torch
  from mmengine.structures import InstanceData
  from mmengine.testing import assert_allclose
  from mmdet.models.task_modules.assigners import UniformAssigner
label_desc: Use image node_id 3 for calling the TestUniformAssigner obj's underlying member method code with example usage: obj.test_uniform_assigner_with_empty_boxes() without return types